The Symetrix 425 is a dual channel compressor/limiter/expander. The two channels may be operated in dual-mono mode, or in stereo mode. In stereo mode, both channels receive identical control signals, which minimizes image shifts caused by unequal gains in the two channels. At Symetrix, we feel that the 425 represents the distillation of our 15 years of signal processing experience into a product that is at once versatile and easy to use without having important controls removed in the interest of simplicity. The 425 is unique because its processor sections are always in-line. There is no selector switch to select between expander, compressor, or limiter. Now you can expand the low-level parts of a signal to improve its signal-to-noise ratio, then apply compression to add punch and density and still have the security of a peak limiter for overload protection. We call this approach to total level control IDP or Integrated Dynamics Processing. IDP also means powerful, streamlined controls that make the 425 easy to learn and quick to set up, even with three types of processing in one rack space. Each section has the controls that you need to respond to any audio situation fast. Individual LED meters show you what's going on inside each section. The 425 is Listed by Underwriters Laboratories Inc. (UL). Samples of this product have been evaluated by UL and meet the applicable UL Standards for Safety. In the final analysis, Integrated Dynamics Processing means clean, quiet sound that meets professional demands in any situation. High-quality components and a minimalist signal path make the 425 exceptionally transparent.